| 摘要 |
PURPOSE: To obtain a crystalline polypropylene improved in rigidity, heat resistance, fatigue resistance, abrasion resistance, dimensional stability, etc., by polymerizing propylene in the presence of a specifiedα-olefin polymerization catalyst component. CONSTITUTION: A solid component consisting essentially of an oxide of a metal selected from the elements of groups II-IV in the periodic table, Mg, Ti, a halogen and an electron-donating compound is brought into contact with an olefin at 100 deg.C or below in an inert medium in the presence of an organoaluminum compound and an organosilicon compound represented by the formula: R<1> Si(OR<2> )x (OR<3> )y (R<1> is a 5-7C alicyclic hydrocarbon; R<2> is methyl or ethyl; x and y are each 1 or 2; and x+y=3) to obtain anα-olefin polymerization catalyst component. Propylene is polymerized in the presence of this component to obtain a crystalline PP having a weight-average molecular weight of 5000-1000000 and satisfying the relationship: Nm >=675-103.1logMw (Nm is the meso average chain length as determined by<13> C-NMR).
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